The present invention relates to a device for insertion in the sole of a shoe to improve foot comfort and support of a person using the shoe.
Shoes, particularly fashionable shoes of the high-heeled type, are normally not designed with foot comfort and support as the primary object. The human foot consists primarily of the heel area, the arch or metatarsal bone area, and the toe area, and the main support areas of the foot are the heel area and the ball of the foot, or the forward ends of the metatarsal bones. The normal shoe sole is a relatively rigid surface, and pressure and friction of the support areas of the foot against this surface often causes discomfort and the development of calluses. At the same time, the normal shoe does not give adequate support to the arch of the foot, often giving rise to walking problems and sometimes resulting in collapsed arches. This problems are aggravated in high-heeled women's shoes, where the foot is urged forward into the toe box of the shoe in walking. The increased pressure on the ball or forefoot regions when wearing such shoes for prolonged periods often gives rise to a burning sensation in these areas of the foot, and substantially increases fatigue and discomfort.
Shoe insert pads have been used in the past to alleviate some or all of these problems. The pads are either of the whole foot variety or designed for localized pressure areas of the foot, and are generally of a flexible cushioning material of some sort, e.g., foam.
Full foot pads are shaped to conform to the contour of the shoe and thus will cushion the entire foot area. Pads of this type are described, for example, in U.S. Pat. No. 1,084,264 of French and U.S. Pat. No. 897,920 of McIntyre.
In addition to pads or insoles designed simply to cushion the foot for the comfort of the shoe wearer, some shoe insert pads are specifically designed to correct or improve walking or posture of the shoe wearer. In U.S. Pat. No. 4,408,402 or Looney, for example, a supportive shoe insert pad is shaped to fit the sole of a shoe but has specific increased support areas in the region of the heel, arch and outer and inner toes of the wearer. In U.S. Pat. No. 4,317,293 of Single et al, an insole pad is cut back behind the big toe area to reduce the rolling of a person's foot towards the outside.
Other shoe insert pads are known which are not shaped to conform to the contour of a shoe, but which are designed to be applied to specific areas of a shoe sole for various purposes. For example, in U.S. Pat. No. 3,316,663 of Neu, a pad which is arched upwardly towards its forward end is designed to fit below the ball of a person's foot to prevent the foot from sliding forward in a shoe. In U.S. Pat. No. 3,265,071 of Kirchmen, a cushioning pad is designed to be fitted below the arch of a foot. in U.S. Pat. No. 2,482,333 of Everston, a heel-less substantially flat pad of multi-layer construction is described, which may be used to add apparent height to the wearer of a shoe. U.S. Pat. No. 2,862,313 of Jones describes insoles having appertures for the insertion of various resilient pads to support the metatarsal support regions of a person's foot. Finally, U.S. Pat. No. 1,976,441 of Feldman describes a cushion foot and arch support which extends from the heel region to a line just before the toe region of a foot.
The usual full foot shoe insert pad tends to creep or slip down into the toe of the shoe and bunch up under the heel and arch, causing discomfort to the wearer of the shoe. This is true of any insert pad which raises the heel within the shoe, since the heel is the region of most movement of a foot in a shoe.